Centering device for plate rolling and lengthening mills

ABSTRACT

The centering device includes a housing and a pair of work centering jaws mounted on respective slide plates movable in the housing by respective racks engaged with a rotatable pinion. The pinion is secured to a vertically oriented shaft connected through a slip-clutch to worm gearing driven by an electric motor. The entire arrangement is shiftable laterally, through one-half the width of the clamping jaw, by a hydraulic actuator. A lower roller support is connected by a linkage to an upper roller support for conjoint movement of the two roller supports in respective opposite directions, and an equalizing linkage assures uniform motion during the height centering operation.

United States Patent 1191 1111 3,803,899 Hertl et al. Apr. 16, 1-974 [5 CENTERING DEVICE FOR PLATE 2,365,322 12/1944 Ashworth 226/199 L G AND LENGTHENING MILLS 2,490,085 12/1949 Nordquist et al. 271/59 2,484,845 10/1949 Nordquist et al 271/59 Inventors: Albert Hertl. Ankerstrasse 2,651,955 9/1953 Fisher 72/250 Werner Iwersen, Blumenthalstrasse both of 41 Dmsburg Germany Primary Examiner-Charles W. Lanham 22 l May 27, 1971 Assistant Examiner-M. J. Keenan [21] A l N 14 531 Attorney, Agent, or Firm-McGlew and Tuttle pp 0.: v 30 I F li t P t D t [57] ABSTRACT 1 M gg g ca [on "on y a 8 202652 I The centering device includes a housing and a pair of ay many work centering jaws mounted on respective slide 1 plates movable in the housing by respective racks eng 72/420 72/ gaged with a rotatable pinion. The pinion is secured to [58] Fie'ld 302 461 a vertically oriented shaft connected through a slip- 72/42O 2l"27]/j58 clutch to worm gearing driven by an electric motor. The entire arrangement is shiftable laterally, through one-half the width of the clamping jaw, by a hydraulic actuator. A lower roller support is connected by a [56] References Cited linkage to an upper roller support for conjoint move- UNITED STATES PATENTS ment of the two roller supports in respective opposite 8,985 l/ 1943 Krieger 226/199 directions, and an equalizing linkage assures uniform :y fi motion during the height centering operation. mit 2,868,540 1/ 1959 Herr 226/199 4 Claims, 3 Drawing Figures nii'ii rii'ii iiiirii TlTTTli CENTERING DEVICE FOR PLATE ROLLING AND LENGTIIENING MILLS BACKGROUND OF THE INVENTION There are already known simple centering devices which are disposed on the outer surfaces of the two working heads of a plate stretcher. These centering devices serve the purpose of laterally centering large sheets or plates horizontally prior to their stretching so that the center of the sheet or plate to be stretched coincides with the center of the stretcher. The heavy sheets and plates are transported by traveling cranes, lowered over the stretcher and held by the cranes during the centering operation. Supporting rolls, whose height level depends upon the respective sheet or plate thickness and which are disposed on the centering device, serve for easy introduction of the plate or sheet ends into the gripper jaws of the stretcher. Alignment of the sheet, in a horizontal direction, if effected by laterally movable centering jaws, through the medium of suitable means such as a spindle having both a right hand thread and a left hand thread.

After this alignment, namely the lateral centering, the expander head of the stretcher moves sufficiently far that the narrower sides of the sheet or plate come into the range of the clamping devices of both working heads. Clamping the plateends in these heads is effected by hydraulically moving wedge-shaped upper and lower clamping jaws, which are juxtaposed in several units, in the direction of the plate width, and of which jaws those corresponding to the respective plate width are used for clamping.

As provided up to the present time, the devices serving to center sheets and plates laterally in plate processing apparatus, such asplate stretchers, enable the centering. jaws only to move in and out, require considerable space, and offer insufficient security against mass forces developing due to unavoidable lateral pendulum motions of the sheet or plate transported by the traveling cranes.

. SUMMARY OF THE INVENTION This invention relates to centering devices for plate and sheet stretchers and, more particularly, to a simple, easily serviced and space saving centering device resistant to rough lateral centering and capable of effecting fine lateral adjustment as well as effecting height adjustment of the entering plates and sheets.

In accordance with the invention, a centering device comprises a housing in which two centering jaws are movably mounted by means of associated slide plates, each respective to a centering jaw, and each connected to a respective rack. The in and out motions of the centering jaws are controlled by an electric gear motor having a slip clutch and a power transmission, this motor rotating a shaft on which there is a pinion meshing with both racks. Lateral forces due to pendulum motions of a sheet or plate transported by a traveling crane are advantageously absorbed elastically by the slip clutch, so that deformation of the curved entering jaws, or inadmissible loads on the parts moving these jaws, are avoided. In order to clamp sheets of definite widths in the best possible manner between the pairs of clamping jaws in the gripper opening of the plate working head, both the centering jaws are movable laterally, i.e. .laterally to the center of the stretcher, by means of another slide plate and a hydraulic cylinder, in particular through the distance of one-half the width of a clamping jaw.

To effect height centering, there is disposed, at the surface of a housing so as to be movable vertically by means of or more hydraulic actuators, a lower roller support which actuates, in the opposite sense and through a linkage including levers, an'upper roller support above the mouth of the plate working head. An equalizing linkage assures uniform motion during the height centering operation, even when the load is unevenly distributed due to crooked or twisted sheets or plates.

An object of the invention is to provide an improved centering device for plate and sheet stretchers.

Another object of the invention is to provide such a centering device which is simple in construction.

A further object of the invention is to provide such a centering device which is easily serviced and which includes space saving machine elements.

Another object of the invention is to provide such a centering device which is capable of withstanding rough lateral centering as well as being capable of effecting fine adjustment and additional centering of the plates and sheets as to height, to displace the sheet or plate by half the width of the clamping jaw laterally and eccentrically to the center of the stretcher.

For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENT The centering device of the invention comprises a three-part housing secured to the forward face of the plate working apparatus. In this housing, which consists of a box 1, a front guide plate 2 and a rear guide plate 3, there are disposed a left rear centering jaw 4 and a right front centering jaw 5 to which are secured respective slide plates 6 each connected to a respective rack 7. Lateral centering, that is, moving of centering jaws 4 and 5 in and out, preferably is accomplished by an electric motor 8 driving a worm gear 9 and a slip clutch 10. Power is transmitted from the slip clutch 10 to the centering jaws by a vertical centrally disposed shaft 11 carrying a pinion l2 meshing with the two racks 7 for conjoint reciprocation thereof in respective opposite directions.

In addition, centering jaws 4 and 5 also can be moved laterally, through a distance equal to one-half the width of the clamping jaws, by a hydraulic cylinder 13 (FIG. 3) through the medium of a slide plate 14 disposed in another housing 15 and supporting pinion l2, shaft 1 l, worm gear 9 and slip clutch 10. During this additional movement, the spacing between centering jaws 4 and 5 is maintained, so that the ends of sheets or plates of certain widths are brought into a more favorable position relative to the pairs of clamping jaws of the plate working apparatus which has not been shown in detail in the drawing.

Two hydraulic actuators 16 are secured to front guide plate 2 and effect height centering of a sheet or plate deposited on lower roller support 17. An equalizing linkage l8 assures uniform horizontal orientation of lower roller support 17 during the height centering operation and even when the load is unevenly distributed due to crooked or twisted sheets or plates. A slide spring 19, interposed between front guide plate 2 and lower roller support 17, serves to absorb horizontally oriented shifting forces during lateral centering movement through a distance of one-half the width of the clamping jaw.

Upper roller support 20 is mounted on the upper surface of the plate working stretcher, so as to be vertically movable in circular guides, which have not been shown, and is actuated, in a contrary sense with respect to lower roller support 17, by lower roller support 17 through external linkages and levers 21. Upper roller support 20 operates on the upper surface of the sheet or plate during the height centering operation. It will be noted that the 8,9 with the slip clutch l0, shaft 11, pinion l2 and rack 7, with slide plate and centering jaws 4 and 5, are arranged together on slide plate 14 which is shiftable transversely of the longitudinal axis of the plate stretching machine through the medium of the hydraulic cylinder 13 which is fixed on the housing 1, 2, 3. This movement has a stroke equal to one-half the width of a clamping jaw.

In inserting a workpiece, a plate to be stretched is fed into the stretching apparatus over the lower roller support 17 provided that the front face of the housing 1, 2, 3, this lower roller support 17 being vertically displaceable by one or more hydraulic cylinders 16. These cylinders, in vertically moving lower roller support 17, move the upper roller support 20, which is above the plate, in a direction opposite to the direction of movement of support 17. Roller support 20 constitutes the clamping jaw for fixing the workpiece in position on roller support 17, and is moved in directions opposite to the movement of lower roller support 17, and an amount equal thereto, through an external link including the levers 21. Thus, both roller supports 17 and 20, acting conjointly, assure a height centering of the workpiece sheet or plate, wich is fed from the right as viewed in FIG. 2.

Full centering of a workpiece, such as a plate or sheet, in order to mount the workpiece accurately in the clamping jaws of the stretcher, is made possible by three superposed movements. The first movement is a lateral centering, by shifting of the centering jaws 4 and 5 on slide plates 6 symmetrically with respect to the longitudinal axis of the stretcher. The second movement is a longitudinal shifting of the entire lateral centering system 8, 9, 10, ll, l2, l4, 6, 7, 4and 5 by the slide plate 14 which mounts the whole lateral centering system. This shifting is effected either to the left or to the right, so that a workpiece, displaced to one side and even assuming an asymmetrical position with respect to the longitudinal axis, may be centered and thereupon be shifted into the symmetrical position. The third movement is the vertical shifting of the roller supports 17 and between which the workpiece sheet or plate is guided, this vertical shifting being effected by the cylinder 16 whereby, through the external linkage levers 21, both roller supports 17 and 20 are centered vertically of the apparatus. By these three simultaneously effective movements, the workpiece can be centered in whatever position it is, and can be subsequently clamped in the jaws of the stretcher.

The provision of slip clutch 10 is particularly important. This absorbs elastically the lateral pendulum movements of a sheet conveyed by a bay crane, so that the damaging of centering jaws 4 and 5 is avoided. Responsive to a lateral impact by the conveyed workpiece, clutch l0 slips, through pinion 12, both jaws 4 and 5 apart, and the workpiece can again be centered. The clutch enablesan absorption of lateral shocks on the jaws due to the pendulum movements of the workpiece during transportation.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing fromsuch principles.

What is claimed is:

l. A centering device, for a sheet and plate stretcher of the type including horizontally oriented work clamping jaws, comprising; in combination, a horizontally oriented housing;

a pair of laterally spaced work centering jaws;

a pair of slide plates movable in said housing and each mounting a respective jaw;

a pair of racks each connected to a respective slide plate;

a pinion rotatable in said housing and meshing with both racks to reciprocate said racks conjointly in respective opposite lateral directions for conjoint movement of said jaws to effect lateral centering of the work;

power means operable to rotate said pinion;

slip clutch means interposed in said power means;

a support plate mounted for reciprocation laterally of the stretcher through a distance equal to one half the length of the work clamping jaws;

an actuator operable to reciprocate said support plate; said support plate mounting said centering jaws, said slide plates, said racks, said pinion, said power means and said slip clutch means for conjoint displacement, with said support plate, longitudinally of the clamping jaws; I

upper and lower vertically spaced laterally elongated roller supports at the front end of said housing for guiding the work into the clamping jaws; and actuator means operable to shift said roller supports simultaneously in opposite vertical directions and through equal distances to center the work vertically with respect to the clamping jaws; said slip clutch means slipping, responsive to a lateral impact on said centering jaws by a workpiece being inserted into the stretcher, to absorb the shock due to such lateral impact by providing for said work centering jaws to move away from each other.

2. A centering device, as claimed in claim 1, in which said power means comprises an electric motor;

gearing driven by said electric motor and connected to said slip clutch means; and a rotatable shaft connected to said slip, clutch means and mounting said pinion.

3. A centering device, as claimed in claim 2, in which said shaft extends substantially vertically at the center of the entering end of the associated stretcher;

said racks being mounted for sliding movement in a and to said housing and operable to maintain horizontal horizontal direction. orientation of said roller supports during height center- 4. A centering device, as claimed in claim 1, including of the work. ing equalizing linkage connected to said roller supports 

1. A centering device, for a sheet and plate stretcher of the type including horizontally oriented work clamping jaws, comprising; in combination, a horizontally oriented housing; a pair of laterally spaced work centering jaws; a pair of slide plates movable in said housing and each mounting a respective jaw; a pair of racks each connected to a respective slide plate; a pinion rotatable in said housing and meshing with both racks to reciprocate said racks conjointly in respective opposite lateral directions for conjoint movement of said jaws to effect lateral centering of the work; power means operable to rotate said pinion; slip clutch means interposed in said power means; a support plate mounted for reciprocation laterally of the stretcher through a distance equal to one half the length of the work clamping jaws; an actuator operable to reciprocate said support plate; said support plate mounting said centering jaws, said slide plates, said racks, said pinion, said power means and said slip clutch means for conjoint displacement, with said support plate, longitudinally of the clamping jaws; upper and lower vertically spaced laterally elongated roller supports at the front end of said housing for guiding the work into the clamping jaws; and actuator means operable to shift said roller supports simultaneously in opposite vertical directions and through equal distances to center the work vertically with respect to the clamping jaws; said slip clutch means slipping, responsive to a lateral impact on said centering jaws by a workpiece being inserted into the stretcher, to absorb the shock due to such lateral impact by providing for said work centering jaws to move away from each other.
 2. A centering device, as claimed in claim 1, in which said power means comprises an electric motor; gearing driven by said electric motor and connected to said slip clutch means; and a rotatable shaft connected to said slip clutch means and mounting said pinion.
 3. A centering device, as claimed in claim 2, in which said shaft extends substantially vertically at the center of the entering end of the associated stretcher; said racks being mounted for sliding movement in a horizontal direction.
 4. A centering device, as claimed in claim 1, including equalizing linkage connected to said roller supports and to said housing and operable to maintain horizontal orientation of said roller supports during height centering of the work. 